These Are the Mouldiest Cities in the UK (2025)

Mould is more than just an eyesore – it’s a growing concern for residents across the United Kingdom. With health risks ranging from respiratory irritation to long-term illnesses, mould can pose a silent threat lurking in bathrooms, kitchens, and behind walls. New research from Mustang Hygiene reveals that in 2025, some UK cities are far more troubled by mould than others, with Manchester leading the pack in search interest per capita. The findings point not only to regional disparities but also to underlying issues related to climate, housing, and infrastructure.

Why Mould Matters – and Where It’s Worse

Mould thrives in damp, poorly ventilated spaces, which makes it a persistent issue in homes with older insulation, limited airflow, or inadequate heating. While the average UK home may face an occasional patch of mildew, some areas report far more frequent concerns, suggesting a deeper and more systemic problem.

According to recent data compiled by the cleaning experts at Mustang Hygiene, Manchester residents made nearly 352 mould-related searches for every 10,000 people in the past year. This rate is 66 percent above the national average and significantly ahead of second-place London.

Here is how the top five cities stack up:

Table 1: Top 5 UK Cities by Mould-Related Searches Per 10,000 Residents

The numbers were calculated through examination of online searches around terms including “mould”, “mould remover”, “how to get rid of mould”, giving a snapshot of regional worry and experience of the issue in people’s homes.

Manchester: Why the UK’s Mould Capital?

But Manchester isn’t just the mouldiest city in the UK, at least in terms of Google interest. Regional surveys and housing data reveal that Greater Manchester and the surrounding area have been plagued by problems related to housing damp for some time. In 2020, approximately 21 per cent of households in the region were found to have serious damp, a known risk factor for mould.

Because the city’s housing stock tends to be old, wet weather patterns tend to be the case, and more rental properties are in play, it is particularly vulnerable, they say. A new housing report by the Greater Manchester Combined Authority also suggests ongoing problems with energy efficiency and insulation – which directly affects the accumulation of moisture inside homes.

In contrast to London’s large total search volume, Manchester’s per capita numbers tell a clearer story: more residents, proportionally, are actively trying to solve or understand mould issues.

Northern Cities Show a Clear Pattern

The data also highlight a North-South divide. Among the top five cities, three are in northern England. Leeds, Manchester, and to some extent Birmingham (which bridges North and Midlands) rank well above southern cities like Southampton, Reading, or Bristol.

This regional clustering aligns with studies from the English Housing Survey, which notes that colder northern climates, combined with aging pre-war housing, contribute to higher instances of damp and mould. The issue is particularly acute in older rental properties where maintenance may lag and tenants have limited control over structural improvements.

Where Mould Is Less of a Concern

Nottingham, by contrast, sits firmly at the bottom of the list, with just 19.7 searches per 10,000 residents. Newport, Sunderland, and Birkenhead also feature among the least mould-affected cities – at least based on search interest.

The low rate in Nottingham is striking. Adjusted for population, Manchester residents are searching for mould solutions nearly 18 times more frequently than those in Nottingham. This could reflect real differences in housing quality, humidity, or public awareness, though further investigation would be needed to confirm.

Table 2: UK Cities with the Lowest Mould-Related Search Interest

Are Searches a Reliable Indicator?

Search behavior can offer insights into public concern, but it is not a perfect proxy for actual mould levels. Some cities may have effective local campaigns that raise awareness, while others may underreport issues due to lack of awareness or access to digital resources.

However, the consistency between search data and known housing issues strengthens the case. The Department of Health and Social Care reports that 4 percent of homes in England experience damp or mould, with rented homes disproportionately affected. Social housing data mirrors this, showing that around 3 to 4 percent of units report damp-related problems, particularly in high-density, lower-income areas.

Daniel Heayberd, operations director at M&A Hygiene Ltd, said, “These findings highlight concerning regional disparities in mould prevalence across UK homes. While total search volumes are highest in London due to its population size, the per-capita analysis shows Manchester residents are facing more widespread mould issues that require urgent attention.”

The Link Between Housing Type and Mould Risk

Mould doesn’t discriminate, but its occurrence often depends on a mix of environmental and socioeconomic factors. Renters, in particular, may be at a disadvantage. Limited control over ventilation systems, reluctance to report issues, or landlords delaying repairs can exacerbate problems.

Old Victorian and Edwardian housing – still common in northern cities – often lacks proper insulation. When heating is expensive or inadequate, condensation can build quickly, creating the ideal conditions for mould to flourish.

Cities with newer developments or more proactive housing authorities – such as Nottingham – may benefit from better preventative infrastructure, contributing to their low search volumes.

Table 3: Mould Concern Score vs. Population Size

What Can Be Done?

Local authorities and housing associations play a key role in mould prevention. Improving insulation, upgrading heating systems, and educating residents about ventilation practices can go a long way. Given the health implications – especially for children, the elderly, and people with respiratory issues – these measures aren’t just preventive, they’re necessary.

Mustang Hygiene urges policy makers to consider these regional patterns when allocating resources or enforcing housing standards. If residents in Manchester are searching for help at significantly higher rates, targeted interventions may be justified.

Meanwhile, property owners – especially landlords – are advised to act quickly on mould complaints. Inaction not only endangers tenants but may also lead to legal consequences under tightening housing laws.

Final Thoughts

Mould is an issue that quietly affects thousands of households every year, often surfacing only when health is compromised or damage is visible. The new research from Mustang Hygiene underscores how certain cities – particularly in the North – face a disproportionately higher burden. With Manchester topping the list and cities like Leeds and Edinburgh following closely, it’s clear that location plays a major role.

But awareness alone isn’t enough. These findings should act as a prompt for local governments, landlords, and housing providers to revisit building standards, prioritize maintenance, and support tenant rights. Mould may grow silently, but the data now speaks loudly.